[PATCH] usb: typec: ucsi: psy: Set current max to 100mA for BC 1.2 and Default
From: Benson Leung
Date: Thu Jul 17 2025 - 16:08:38 EST
ucsi_psy_get_current_max would return 0mA as the maximum current if
UCSI detected a BC or a Default USB Power sporce.
The comment in this function is true that we can't tell the difference
between DCP/CDP or SDP chargers, but we can guarantee that at least 1-unit
of USB 1.1/2.0 power is available, which is 100mA, which is a better
fallback value than 0, which causes some userspaces, including the ChromeOS
power manager, to regard this as a power source that is not providing
any power.
In reality, 100mA is guaranteed from all sources in these classes.
Signed-off-by: Benson Leung <bleung@xxxxxxxxxxxx>
---
drivers/usb/typec/ucsi/psy.c | 2 +-
drivers/usb/typec/ucsi/ucsi.h | 7 ++++---
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/typec/ucsi/psy.c b/drivers/usb/typec/ucsi/psy.c
index 62ac69730405..62a9d68bb66d 100644
--- a/drivers/usb/typec/ucsi/psy.c
+++ b/drivers/usb/typec/ucsi/psy.c
@@ -164,7 +164,7 @@ static int ucsi_psy_get_current_max(struct ucsi_connector *con,
case UCSI_CONSTAT_PWR_OPMODE_DEFAULT:
/* UCSI can't tell b/w DCP/CDP or USB2/3x1/3x2 SDP chargers */
default:
- val->intval = 0;
+ val->intval = UCSI_TYPEC_DEFAULT_CURRENT * 1000;
break;
}
return 0;
diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index b711e1ecc378..ebd7c27c2cc7 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -483,9 +483,10 @@ struct ucsi {
#define UCSI_MAX_SVID 5
#define UCSI_MAX_ALTMODES (UCSI_MAX_SVID * 6)
-#define UCSI_TYPEC_VSAFE5V 5000
-#define UCSI_TYPEC_1_5_CURRENT 1500
-#define UCSI_TYPEC_3_0_CURRENT 3000
+#define UCSI_TYPEC_VSAFE5V 5000
+#define UCSI_TYPEC_DEFAULT_CURRENT 100
+#define UCSI_TYPEC_1_5_CURRENT 1500
+#define UCSI_TYPEC_3_0_CURRENT 3000
struct ucsi_connector {
int num;
--
2.50.0.727.gbf7dc18ff4-goog